Collection means for a mobile vacuum apparatus for the collection of liquid or semi-liquid materials

ABSTRACT

The apparatus comprises a front-mounted collection means for a vacuum tank for the collection of liquid or semi-liquid materials. The collection means comprises a substantially V-shaped housing with a scraper at the bottom thereof, a height adjustable suction inlet at the apex thereof, and a pair of laterally adjustable pivoting wings for varying its width to correspond to that of an alley or gutter. A plurality of rotary feeders, each having a vertical axis of rotation, are mounted to the housing adjacent the scraper to prevent accumulation of the materials on the scraper. The feeders do not contact either the surface upon which the scraper is operated, nor the scraper itself, but serve to mix thick consistency materials with thinner consistency materials and also to dislodge any accumulation that does occur.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 11/113,303, filed on Apr. 25, 2005.

FIELD OF THE INVENTION

The invention relates to the mobile pneumatic collection of liquid orsemi-liquid materials such as animal manure. More specifically, theinvention relates to a collection means for mounting beneath a mobilevacuum apparatus to direct the liquid or semi-liquid materials into asuction inlet when the apparatus is driven through the materials.

BACKGROUND OF THE INVENTION

Animal husbandry facilities, such as dairy or hog barns, include alleysor gutters for manure collection. Vehicles such as tractors orskid-steer loaders are equipped with scraper blades or front-end bucketsystems to transfer manure accumulated in the alley or gutter to one endof the barn for removal and disposal. The manure is typically liquid orsemi-liquid and is often difficult to transfer in this manner, as itescapes around the sides of the scraper blade or bucket. In addition,with the very large facilities that are becoming quite common in moderndairy farming, sometimes with an overall length in excess of 1000 feet,the quantity of accumulated material is too great to transfer to one endof the facility. As a result, there is a need for improvements in thecollection and removal of manure from animal husbandry facilities.

Pneumatic collection of agricultural debris is used in a variety ofoperations both on and off the farm. For example, in the clean-up ofspills of dry solid materials, such as grain or agricultural chemicalslike fertilizer, vacuums are employed to pneumatically transfer thespilled materials to a storage container. An example of such a vacuumapparatus is provided in U.S. Pat. No. 4,218,226. These types ofmachines are not particularly well-suited to the collection of liquid orsemi-liquid materials such as animal waste. Moreover, they lack any typeof collection means for mounting beneath the apparatus to direct thecollected material to the suction inlet when the apparatus is drivenover the material, making them difficult to use in large scale mobilecleanup operations.

Vacuum systems have been used for mobile cleanup of relatively drymanure, such as chicken and horse manure. U.S. Pat. No. 5,010,620discloses a stall and pasture vacuum machine that includes a frontmounted sled comprising a rotary brush. A mist of water may be providedto soften the manure and make it more amenable to pneumatic conveying.The collected manure is stored in a dump box with a hinged rear door.This machine is not suitable for the cleanup of liquid or semi-liquidmaterials.

Vacuum systems have been used in the clean-up of liquid and semi-liquidanimal waste. U.S. Pat. No. 3,585,670 discloses an apparatus comprisinga vacuum tank and a rear-mounted V-shaped scraper blade. However, inmounting the scraper blade at the rear of the apparatus, the manure iscompacted prior to being collected, making it difficult to separate fromthe barn floor and difficult to convey pneumatically.

Another vacuum apparatus for the collection of liquid or semi-liquidmanure is manufactured by Loewen Welding & Manufacturing (Matsqui, BC,Canada) under the trade-name Honey-Vac®. In this apparatus, thecollected manure enters the back of the vacuum tank from the topthereof. Since the collected manure is also discharged from the back,there is no complete flushing from front to rear during discharge. Thisleads to an accumulation of manure in the front of the tank thatdiminishes tank capacity after repeated use. The accumulated manure mustbe periodically cleaned out through manual access hatches, which is adangerous and unpleasant task. Also, the apparatus makes use of separateblower and vacuum pumps, which creates mechanical complexity andincreases down time.

As a result, there remains a need for an improved material collectionapparatus, particularly for liquid and semi-liquid materials such asanimal manure.

SUMMARY OF THE INVENTION

According to an aspect of the present invention, there is provided amobile vacuum apparatus for collection of liquid or semi-liquidmaterials, the apparatus comprising: a frame having a front and rear; aset of wheels mounted under the frame; a vacuum tank for receivingcollected liquid or semi-liquid materials, the vacuum tank having avacuum inlet at a front thereof and a vacuum outlet at a top thereof; acollection means comprising a scraping element mounted under the frontof the frame, the collection means in fluid communication with thevacuum inlet; a discharge outlet at a rear of the tank; and, a blowervac capable of drawing air from the vacuum tank through the vacuumoutlet to thereby create a vacuum in the tank.

According to another aspect of the invention, there is provided a mobilevacuum apparatus for collection of liquid or semi-liquid materials, theapparatus comprising: a frame having a front and rear; a set of wheelsmounted under the frame; a vacuum tank for receiving collected liquid orsemi-liquid materials, the vacuum tank having a vacuum inlet at a frontthereof and a vacuum outlet at a top thereof; a collection means influid communication with the vacuum inlet; a discharge outlet rearwardof the collection means; a blower vac selectively capable of eitherdrawing air from the vacuum tank through the vacuum outlet to therebycreate a vacuum in the tank or blowing air into the vacuum tank tothereby expel the collected liquid or semi-liquid materials therefromunder pressure through the discharge outlet; and, a valve means fordirecting air to a blower vac exhaust when drawing air from the vacuumtank and for supplying air from an elevated blower vac intake whenblowing air into the vacuum tank.

The apparatus is mobile and may be either pulled by a towing vehicle orself-propelled. The towing vehicle may be a farm tractor and theapparatus is particularly suitable for agricultural use. The apparatusis designed to be driven over the material to be collected with thecollection means in front to reduce compaction of the material beingcollected. The material being collected may be any type of liquid orsemi-liquid material suitable for pneumatic conveying. The material maycomprise liquid waste. The material may comprise animal manure, such asmanure from cows or pigs, and the animal manure may be in a semi-liquidstate. The apparatus may be adapted for use in an animal husbandryfacility, such as a dairy barn or milking shed, particularly such afacility that includes alleys or gutters for collection of manure.

It is desirable that the collected material is prevented from enteringthe blower vac, as obstruction of its internal moving parts can causesignificant damage to the blower vac. The vacuum tank includes a vacuumoutlet that may comprise two or more vacuum outlets spaced apart alongthe top of the tank. By using two or more vacuum outlets, the velocitythrough each outlet is decreased, thereby reducing the likelihood thatthe collected material can become entrained in the air flowing throughthe outlets. The outlets may be of the same size or different sizes inorder to preferentially direct the collected material to different partsof the tank. Each outlet may include a primary trap to further reducethe likelihood of material escaping through the vacuum outlet,particularly when the tank is full. Any suitable primary trap design maybe used and the primary trap is preferably readily cleaned by reducingthe air flow through the vacuum outlet.

Air flowing from the vacuum outlet may be directed to a secondary trapfor yet further reducing the likelihood that entrained debris will enterthe blower vac. The secondary trap may be of any suitable design and maycomprise a chamber containing a series of baffle plates that arearranged to create a serpentine path. Alternatively, the chamber maycontain a plurality of perforated impingement plates stacked with theperforations in an offset relationship. The secondary trap may besimilar to a knock-out pot in that it may be designed for the removal ofliquid from the air flow, particularly liquid droplets. The secondarytrap may be cleaned by reversing the direction of air flow through thetrap and may be additionally or alternatively cleaned using asupplemental stream of air or water to flush out the contents of thetrap. The secondary trap may include a drain and the drain may bedirected back into the vacuum tank. The outlet of the secondary trap ispreferably free of collected material or droplets and is provided to theblower vac.

The blower vac may be powered by a motor of the towing vehicle or by amotor mounted on the apparatus itself. A separate motor may be used toindependently power the blower vac. The towing vehicle may be connectedto the blower vac using a power take-off (PTO) mechanism. The blower vacmay comprise a single unit or two separate but connected units. Theblower vac may comprise two chambers connected to a single power source.The blower vac may comprise an internal valve that permits the flow paththrough the blower vac to be altered in order to switch the intake portof the blower vac to the exhaust port and vice versa. The blower vac maybe reversible in order to alternate intake and exhaust ports. The blowervac may comprise a positive displacement pump, such as a rotary vanepump. The blower vac may be in fluid communication with a valve means.

The valve means may be used as part of any liquid or semi-liquidmaterial collection system that both draws and expels materialpneumatically. The valve means may be automatically adjustable ormanually adjustable. The valve means may comprise a three-way valvemechanism that permits selection of a single flow path from twodifferent flow paths, for example and L-ported ball valve that may bealternated between two flow paths. The valve means may comprise a pairof check valves, one check valve in each of the intake and exhaust flowpaths. The check valves may be oppositely oriented to permit air to flowinto the valve means through only one flow path (the intake flow path)and out of the valve means by only the other flow path (the exhaust flowpath). In this manner, the valve means is automatically adjustable inresponse to a change in the direction of flow through the blower vac.The valve means may include a valve chamber and the check valves neednot necessarily both be located in the valve chamber. The valve means isparticularly advantageous in allowing an air intake and exhaust of thesystem to be separated, thereby permitting the intake to be elevatedwith respect to the material being collected and the exhaust to belocated distantly from the operator. The elevated exhaust reduces thelikelihood of debris entering the blower vac when blowing air into thetank and the distant exhaust improves operator health and safety.

The collection means may be any suitable mechanism for directing thematerial toward the pneumatic collection inlet and may include, forexample a brush, rotating brush, scraper, squeeqee, air blast, waterjet, or a combination thereof. The scraper may comprise a scrapingelement made from a rigid yet flexible material, such as a highdurometer or reinforced rubber. The collection means may be heightadjustable and may be either self-leveling or manually level adjustedwith respect to the material collection surface. The suction inlet ofthe pneumatic collection system may be through a distribution means topermit collection across the width of the collection means or collectionmay occur at a discrete point or points. The collection means may have ashape adapted for funneling the material toward the suction inlet, forexample a V-shape when seen in plan view.

The suction inlet may be height adjustable independently of any heightadjustment of the collection means in response to the quantity ofmaterial being collected; this permits a scraping element of thecollection means to remain in contact with the floor surface whileallowing the suction inlet to be adjusted relative in height thereto inresponse to a large quantity of material being collected. Any suitablemechanism may be employed to adjust the height of the suction inlet. Thesuction inlet is preferably connected to the vacuum inlet by a flexibleconnection in order to facilitate the height adjustment. By setting thesuction inlet closer to the floor surface that the material is beingcollected from more material may be collected, thereby leaving lessmaterial in the collection means at the end of a pass through an alley.However, if set close to the floor, the suction inlet will have morematerial to pick-up and driving speed may have to be reduced. There istherefore an optimal trade-off between speed and completeness ofcollection. A snorkel may be provided alongside the suction inlet forintroducing a small quantity of air into the material as it is beingcollected. This small quantity of air is entrained with the material andmakes it easier to lift from the floor and easier to pneumaticallyconvey, particularly for materials with a thick consistency. The snorkelmay include a small valve to set the quantity of air provided to thesuction inlet according to the consistency of the material beingcollected.

The collection means may include a variable width mechanism. Thevariable width mechanism is particularly useful in the collection ofmanure from alleys or gutters, as it allows the collection means to fitthe width of the alley or gutter and reduces the likelihood of manureescaping around the sides of the collection means. The collection meansmay include wings that are pivotally attached to each side of thecollection means and able to pivot about a vertical pivot axis. Thewings may be biased outwardly towards or against the sidewalls of thealley or gutter and may resiliently adapt to changes in the width of thegutter by pivoting about the vertical pivot axis. The wings may moveabout the vertical pivot axis in response to a change in the distancebetween the side-wall of the alley and the collection means. The wingsmay be biased by a spring means or a suitable fluid cylinderarrangement, such as a pneumatic or hydraulic fluid displacementcylinder, a captive gas shock absorber, or a combination thereof. Thewings may automatically adjust to the width of the alley or gutter ormay be manually adjusted by an operator of the apparatus. The adjustmentmay be conducted using controls within the towing vehicle. The wings mayinclude skid plates or wear strips to reduce the likelihood of damagingthe wings due to operator driving error.

The discharge outlet is provided at the rear of the vacuum tank. Thedischarge outlet may be connected to any manure distribution systemsuitable for liquid or semi-liquid manure, such as a spreader plate orsub-surface injection system. Alternatively, the discharge outlet may beconnected via a fluid conduit for transferring the manure to a separatespreading apparatus or a holding vessel. The vacuum inlet is provided atthe front of the tank, preferably in a lower half thereof below thehorizontal midline of the tank. Filling the tank from the front anddischarging the tank through the rear causes a flushing of the collectedmaterials through the tank. This causes substantially all of thematerial in the tank to be discharged and mitigates material build-up inthe front of the tank. During collection, a remotely operable valve onthe discharge outlet is closed to prevent inadvertent leakage fromoccurring. During tank discharge, a remotely operable valve on thevacuum inlet is closed to prevent material from being discharged throughthe collection means.

Further features of the invention will be described or will becomeapparent in the course of the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

In order that the invention may be more clearly understood, embodimentsthereof will now be described in detail by way of example, withreference to the accompanying drawings, in which:

FIG. 1 a is a side view of the apparatus according to the presentinvention showing a flow path through the apparatus when material isbeing collected;

FIG. 1 b is a side view of the apparatus according to the presentinvention showing a flow path through the apparatus when material isbeing discharged;

FIG. 2 is a side view of an embodiment of a collection means accordingto the present invention;

FIG. 3 is a top view of the collection means of FIG. 2;

FIG. 4 is a side view of the height adjustable suction inlet of thepresent invention;

FIG. 5 a is a schematic side view of the valve means of the presentinvention while air is being drawn from the vacuum tank;

FIG. 5 b is a schematic side view of the valve means of the presentinvention while air is being blown into the vacuum tank;

FIG. 6 is a perspective view of another embodiment of a collection meansaccording to the present invention;

FIG. 7 a is a front view of the collection means of FIG. 6;

FIG. 7 b is a bottom view of the collection means of FIG. 6; and,

FIG. 8 is a bottom perspective view of a rotary feeder for thecollection means of FIG. 6.

DESCRIPTION OF PREFERRED EMBODIMENTS

In describing the figures, like features are referred to by likereference numerals. Although not all features indicated on a particulardrawing are necessarily described with reference to that drawing, all ofthe features are described with reference to at least one of thedrawings.

Referring to FIGS. 1 a and 1 b, the mobile vacuum apparatus comprises avacuum tank 1 mounted on a frame 2 having a front and rear with a hitchmeans 3 for connection to a towing vehicle (not shown) at the front ofthe frame. A collection means 4 is mounted to the underside of the frame2 at the front thereof, forward of a discharge outlet 5 of the vacuumtank 1. A spreader means 6 is attached to a flange on the dischargeoutlet 5. A set of tandem wheels 8 is mounted to the underside of theframe 2 using a walking-axle arrangement as is conventionally known.

A blower vac 7 is provided at the front of the frame 2. The blower vac 7is a positive displacement rotary vane pump (in a preferred embodiment,a Wallenstein type pump) that can operate as either a blower or vacuumpump. The blower vac 7 is a single integrated unit capable ofselectively drawing air from the vacuum tank or blowing air into thevacuum tank. An integral valve (not shown) is provided as part of theblower vac 7 to switch between drawing air from and blowing air into thevacuum tank 1. The pump derives power from the towing vehicle via a PTOshaft 15.

FIG. 1 a schematically shows a flow path through the apparatus whenmaterial is being collected. The collection means 4 is lowered withrespect to ground level and parallel thereto with a scraper element 14in contact with the floor surface. Material is admitted into a suctioninlet (not shown in FIGS. 1 a and 1 b) of the collection means 4 anddrawn through suction conduit 37 into vacuum inlet 16 of vacuum tank 1.The vacuum inlet 16 is located on the front of the vacuum tank 1 in thelower half thereof below the horizontal midline of the tank. This causesthe collected material to fill the tank from front to rear, improvingweight distribution and facilitating substantially complete discharge.The air is then drawn out of the vacuum tank 1 through vacuum outlet 17,which comprises front vacuum outlet 17 a and rear vacuum outlet 17 b.The use of two vacuum outlets 17 a and 17 b reduces the exit airvelocity by half as compared with a single outlet, significantlyreducing the likelihood of debris becoming entrained and exiting throughthe vacuum outlet 17. Each vacuum outlet 17 a and 17 b is equipped witha primary trap 23 comprising a stainless steel ball float 18 captivatedwithin a rigid mesh cage 19. The rigid mesh cage 19 helps preventmaterial from exiting the tank 1 through the vacuum outlet 17. As thelevel of material in the vacuum tank 1 rises to the top of the tank, thefloat 18 rises and blocks the outlet 17 to prevent material from beingdrawn out of the tank. The primary trap 23 therefore serves as a firstline of defense in keeping the collected material within the tank 1.

Air drawn through the vacuum outlet 17 is next directed into secondarytrap 21 at the bottom thereof. The secondary trap 21 includes aplurality of stacked baffles 22 arranged to create a serpentine flowpath through the trap 21. This causes disengagement of any materialsentrained in the air flow, particularly liquid materials which may havepassed the mesh cage 18 of the primary trap 23. The secondary trap 21includes a drain (not shown) for re-introducing any collected materialback into the vacuum tank 1. The secondary trap 21 may be cleaned usingsupplementary flows of water or air provided through ports (not shown)at the top thereof. The exit of the secondary trap 21 is protected by astainless steel ball float 18 captivated within a rigid mesh cage 19 inan arrangement similar to that of the primary trap 23.

Air exiting the secondary trap 21 is provided to the blower vac 7through first blower vac conduit 24 and exits therefrom through secondblower vac conduit 26. The air is provided to a valve means comprising avalve chamber 50 and pressurizes the valve chamber, causing the secondclosure means 60 to open and allowing the air to exit through theanterior end of blower vac exhaust 52.

In FIG. 1 b, the apparatus is illustrated in a tank discharge condition.The blower vac 7 creates a negative pressure or vacuum in the valvechamber 50. This causes the first closure means 54 to open, admittingair into the valve chamber 50 through blower vac intake 51. The air thenflows through the second blower vac conduit 26 into the blower vac 7,which acts to blow the air out through first blower vac conduit 25. Theair flows downwardly through the secondary trap 21, back flushing anyaccumulated debris out through the drain (not shown) and into tank 1.The air then passes out of the bottom of the secondary trap 21 and intothe vacuum outlet 17 at the top of the vacuum tank 1. The primary trap23 is back flushed to dislodge any debris accumulated against the meshcage 19. A positive pressure is created in the vacuum tank 1, whichforces the collected material outwardly through rear discharge outlet 5.A remotely operable discharge valve (not shown) is opened duringdischarge to allow material to exit through the spreader means 6 and isclosed during collection of material. Conversely, a remotely operablesuction valve (not shown) is closed during tank discharge to preventmaterial from exiting through the collection means 4 and is openedduring collection of material.

The introduction of air through the first vacuum outlet 17 a causesmaterial accumulated at the front of the tank to be pushed downwardlyand out through the discharge outlet 5. In this manner, a completeflushing of the vacuum tank 1 occurs to expel substantially all of thematerial in the tank (as compared with prior art systems) reducing theneed for manual cleanout of the front of the vacuum tank.

Referring to FIGS. 2 and 3, the collection means 4 is pivotally mountedto the underside of the frame 2 by way of pivot arm 10. Pivot arm 10 ispivotally attached at one end to a central portion 29 of the collectionmeans 4 at first pivot pin 27 and at the other end to the frame 2 atsecond pivot pin 28, which is located between the tandem wheels 8. Ahydraulic lift cylinder 9 is provided between the central portion 29 andthe frame 2 and may be extended or retracted to lower or raise,respectively, the collection means 4 by pivoting of the pivot arm 10about the second pivot pin 28. The collection means 4 is typicallyraised when turning the apparatus to prevent damage to the collectionmeans due to skid-induced lateral forces.

An adjustable length link 11 is pivotally attached at one end to anupwardly extending stub 12 fixedly mounted on the pivot arm 10. Theother end of the link 11 is pivotally attached to the central portion 29at link pivot 13, which is located above the first pivot pin 27. Byadjusting the length of the link 11, a fine tilting adjustment of thecentral portion 29 may be attained so as to ensure that the scraperelement 14 attached to the underside of the collection means 4 remainsin contact with the floor or other surface from which the materials arebeing collected. The scraper element 14 comprises a high durometerrubber scraping edge with a steel reinforcement. This permits thescraping element 14 to conform somewhat to irregularities in the scrapedsurface while providing sufficient rigidity to remove adherentmaterials. The rubber scraping edge also provides a squeegee effectsimilar to an automotive windshield wiper that permits liquid orsemi-liquid materials to be scraped.

The collection means 4 further comprises a pair of laterally adjustablewings 30 that are attached to the central portion 29 on opposite sidesthereof. Each wing 30 is pivotally attached to the central portion 29using a piano hinge 31 that allows the wing to pivot about a verticalpivot axis passing through the center of the hinge. A hydraulic wingcylinder 32 is pivotally attached to each wing 30 and to central portion29 so that extension of the wing cylinders causes the wings to open,thereby increasing the width of the collection means 4. The wings 30 areclosed by retracting the wing cylinders 32. The normal range of movementof the wings 30 is from a closed position parallel to the longitudinalaxis of the apparatus (defined by its direction of travel) to an openposition which is at an angle less than perpendicular to thelongitudinal axis and preferably tangential to the central portion 29 atthe hinges 31. FIG. 3 shows the closed position (marked A) and alsoshows the open position (marked B) in phantom lines. In the openposition, the wings 30 extend past the wheels 8. The wings 30 arenormally closed when transporting the apparatus to reduce the risk ofdamaging the wings.

The wings 30 may be controlled using a single circuit so that they bothopen and close at the same time or using separate circuits so that oneor the other of the wings may be opened or closed. In addition, thewings 30 need not be completely opened, but can be set to any desiredangle of opening. This is particularly advantageous when scraping alarge area without side-walls. When scraping an alley or gutter withside-walls, such as in an animal husbandry facility, the wings 30 arepreferably opened until a skid protector 33 attached to the distal endof each wing comes into contact with the side-wall. The skid protector33 may be made from metal or a durable plastic, preferably a plasticwith dry lubricant qualities such as Delrin®. A pressure relief valve(not shown) is provided in each hydraulic circuit of the wing cylinders32 in order to permit the wings 30 to close by rotating about thevertical pivot axis in response to a decrease in distance between thecollection means 4 and the side-wall. The valves may be adjusted tomaintain a modest cylinder extension pressure so that the wings 30return to the desired pre-set open position when the distance betweenthe collection means 4 and the side-wall increases. The net effect isthat closing of one wing 30 due to distance changes while driving ismatched by a corresponding opening of the opposite wing.

A height adjustable suction inlet 20 is provided at about the center ofthe central portion 29. Referring to FIG. 4, the suction inlet 20 has a45° bend so that a lower portion 34 forms a downwardly oriented nozzleopening 35 that is roughly parallel with the floor (subject to finelevel adjustment using adjustable length link 11). The upper portion 36of the suction inlet 20 is attached one end of flexible suction conduit37. The other end of suction conduit 37 is attached to the vacuum inlet16 of vacuum tank 1. The flexible suction conduit 37 permits the heightof the suction inlet 20 to be adjusted without constraint by theconduit. An upright post 38 is fixedly attached to the suction inlet 20.The central portion 29 has an inverted L-shaped cross-section with a topportion 39 to which a collar 40 is mounted. The collar 40 is forwardlyoffset from the central portion 29 and has a bore that is complementaryin size to the upright post 38. The bore permits sliding passage of theupright post 38 through the collar 40. A user-adjustable set screw 41 isprovided in the collar 40 for threading engagement with the upright post38. By loosening the set screw 41, the upright post 38 is permitted toslide through the bore of the collar 40, allowing the height of thesuction inlet 20 to be raised or lowered relative to ground level.Tightening the set screw 41 allows the desired height of the suctioninlet 20 to be fixed. During forward travel of the apparatus in thedirection indicated by arrow C, the liquid or semi-liquid material beingcollected accumulates within the inverted L-shaped cross section of thecentral portion 29 and is constrained from overflowing by the topportion 39 thereof. The height of the suction inlet 20 is typicallyadjusted higher for thick semi-liquid materials and lower for liquidmaterials. In an alternative embodiment, the height of the suctionnozzle may be adjusted by an operator within a tractor or towing vehicleusing hydraulic controls.

A snorkel 43 is provided alongside the suction inlet 20. The snorkel 43permits a small quantity of air to be introduced into the opening 35 forentrainment with the materials being collected by the suction inlet 20.It has been found that the introduction of air by the snorkel 43 is ofparticular use in the collection of thick semi-solid materials, as thetwo-phase flow produced tends to aid in pneumatically conveying thematerials into the vacuum tank 1. A snorkel valve 44 may be adjusted todeliver the desired amount of air to the suction inlet 20 according tothe consistency of the materials being collected.

Referring to FIGS. 5 a and 5 b, a valve means is schematically shown aspart of the blower vac intake/exhaust system. A valve chamber 50 isprovided with an elevated blower vac intake 51 extending upwardlytherefrom and a blower vac exhaust 52 extending downwardly therefrom.The second blower vac conduit 26 extends from the side of the valvechamber 50 and permits flow in either direction between the blower vac 7and the valve chamber. The second blower vac conduit 26 is preferablyprovided tangentially to the valve chamber 50 and laterally offset fromthe vertical centerline thereof to create a swirling flow pattern andcyclonic action within the valve chamber. The valve chamber 50 can beshaped and/or include supplementary flow elements to enhance this flowpattern. The cyclonic action is used as an aid in removing dust ordebris when the blower vac intake 51 is being used to supply air forblowing into the vacuum tank 1.

FIG. 5 a shows the valve means in operation when drawing air from thevacuum tank 1. A first closure means 54 is pivotally attached to thelower end of the blower vac intake 51 within the valve chamber 50 byclosure hinge 55. The first closure means 54 has a counterweight 56 onan opposite side of the closure hinge 55 from the blower vac intake 51.The counterweight 56 biases the first closure means 54 into a closedposition to seal the end of the blower vac intake 51. The valve chamber50 is pressurized when air is drawn from the vacuum tank 1 and the airpressure helps maintain the first closure means 54 in a closed position.The pressurized air escapes through blower vac exhaust 52. The blowervac exhaust 52 is downwardly oriented from the valve chamber 50 and isrouted along the underside of the frame 2. An opening at the anteriorend of the blower vac exhaust 52 directs the foul-smelling air drawnfrom the vacuum tank 1 downwardly and away from the operator of theapparatus, who is located in the towing vehicle attached to the fronthitch means 3. This improves the overall health and safety of theoperator. A second closure means 60 is pivotally attached to theanterior end of the blower vac exhaust 52. A closure weight 61 isprovided to bias the second closure means 60 into a closed position overan opening in the anterior end of the blower vac exhaust 52. However,the flow of pressurized air provided from the valve chamber 50 issufficient to overcome this bias and causes the second closure means 60to open, thereby allowing air to escape through the opening.

Referring to FIG. 5 b, the valve means is shown in operation during tankdischarge when the blower vac 7 is used to blow air into the vacuum tank1. The flow path through the second blower vac conduit 26 is reversed ascompared with FIG. 5 a and the valve chamber 50 is under vacuum. Thevacuum overcomes the bias provided by the counterweight 56 and causesthe first closure means 54 to open, admitting air into the valve chamber50 through the blower vac intake 51. A filter 59 is provided atop theblower vac intake 51 to remove debris from the intake air stream inorder to reduce the potential for damage to the blower vac 7. Thenegative pressure within the valve chamber 50 enhances the bias on thesecond closure means 60 provided by the closure weight 61 and acts toseal the blower vac exhaust 52.

By referring to FIGS. 5 a and 5 b, it can be seen that the first andsecond closure means 54 and 60 of the valve means act as oppositelyoriented check valves that permit flow in only one direction througheach of the blower vac intake 51 and blower vac exhaust 52. The valvemeans permits flow through one flow path or the other, depending on thedirection of flow through the second blower vac conduit 26. The firstand second closure means 54 and 60 automatically close or open accordingto whether air is being drawn from the vacuum tank 1 or blown into thevacuum tank 1.

Referring to FIGS. 6 and 7 a-b, an alternative embodiment of acollection means for use with the mobile vacuum apparatus is shown. Thecentral portion 29 of the collection means comprises two forward angledsides 70. Each of the sides 70 has a scraper element 14 located at abottom thereof for accumulating the liquid or semi-liquid materialswithin an interior 71 of the central portion 29 when the apparatus is inuse. The forward angled sides converge at an apex 72 such that thecentral portion 29 appears substantially V-shaped when seen in top view.In another alternative embodiment, the central portion 29 appearstrapezoidal when seen in top view. The suction inlet 20 is located at amiddle of the central portion 29, adjacent the apex 72. In order toprevent the collected materials from overflowing the interior 71, thecentral portion 29 is provided with a top flange 73, which causes it tohave the aforementioned inverted L shaped vertical cross-section. Thewing cylinders 32 are pivotally mounted to the top flange 73 in order topermit the wings 30 to pivot about the piano hinge 31 as previouslydescribed. Each wing is equipped with a scraper element 14 at a bottomthereof and a skid protector 33, as previously described, to permit thewings to open in order to vary the width of the collection means 4 tomatch the width of the alley or gutter being scraped.

During the collection of certain semi-liquid materials, particularlythose with a thick and/or sticky consistency, there can be a tendencyfor accumulation to occur along the scraper element, thereby interferingwith proper operation of the vacuum apparatus. To help mitigate thisproblem, the collection means 4 is provided with a plurality of rotaryfeeders 74 located adjacent the scraper element within the interior 71.Preferably, there is at least a rotary feeder 74 provided on either sideof the suction inlet 20. More preferably, there is at least a rotaryfeeder 74 provided on either side of the suction inlet 20 and at least arotary feeder 74 provided on each wing 30.

Referring additionally to FIG. 8, each rotary feeder 74 is equipped witha hydraulic motor 77 mounted atop a feeder mounting bracket 79. Thehydraulic motor 77 is mounted to provide a vertical axis of rotation 78.A set of radially extending protrusions 75 concentric with the axis 78is mounted to the output shaft of the motor 77 below the bracket 79. Theprotrusions 75 are substantially scoop shaped, curving away from thedirection of rotation of the motor 77, although need not necessarily beso. Each protrusion 75 is rigid and equipped with a downwardly extendinglip 76 on the bottom thereof. Use of an independent hydraulic motor 77for each rotary feeder 74 allows the rotational speed of each feeder tobe adjustable, if so desired. The rotational speed is determinedaccording to the consistency of the materials being collected, theheight of the suction inlet 20 and/or the rate of travel of the mobilevacuum apparatus. The rotational speed may be adjusted by an operator ofthe tractor used to pull the apparatus; for example, one, two or moresets of hydraulic remotes may be employed and the speed of the connectedmotors may be adjusted using a control lever located in the tractor. Twoor more motors may be connected in parallel to a set of hydraulicremotes. In one embodiment, the rotational speed of the rotary feeders74 on the wings 30 is separately adjustable from the rotational speed ofthe rotary feeders 74 on the central portion 29, since more materialaccumulates near the apex 72 and hence a higher speed is sometimesneeded for the feeders 74 closest to the suction inlet 20.

Referring particularly to FIG. 7 a, it is important to note that theheight of the rotary feeders 74 is elevated with respect to groundlevel, typically by an amount of from 1 to 2 inches. In other words, therotary feeders are not in contact with the ground, nor with the scraperelement 14. The feeders 74 simply function to reduce accumulation ofmaterial adjacent the scraper element 14 by mixing thinner material withthicker material in order to make it more amenable to scraping. In theevent that a significant amount of material does accumulate, the feeders74 dislodge the material in order to transfer it towards the apex 72.

Other advantages which are inherent to the structure are obvious to oneskilled in the art. The embodiments are described herein illustrativelyand are not meant to limit the scope of the invention as claimed.Variations of the foregoing embodiments will be evident to a person ofordinary skill and are intended by the inventor to be encompassed by thefollowing claims.

1) A collection means for use with a mobile vacuum apparatus for thecollection of liquid or semi-liquid materials, the collection meanscomprising: a) a central portion having an interior within which thematerials are collected; b) at least one scraper element at a bottom ofthe central portion; c) a suction inlet located at a middle of thecentral portion; and, d) a plurality of rotary feeders within theinterior of the central portion adjacent the scraper element, eachrotary feeder having a vertical axis of rotation and comprising aplurality of radially extending protrusions for engagement with thecollected material. 2) The collection means according to claim 1,wherein the central portion comprises at least two forward angled sidesfor guiding the collected material toward the suction inlet when theapparatus is in use. 3) The collection means according to claim 2,wherein the central portion is substantially trapezoidal or V-shaped intop view. 4) The collection means according to claim 3, wherein thesuction inlet is located at an apex of the central portion. 5) Thecollection means according to claim 2, wherein there is a scraperelement provided at the bottom of each forward angled side. 6) Thecollection means according to claim 1, wherein at least one rotaryfeeder has a rotational speed that is adjustable. 7) The collectionmeans according to claim 1, wherein at least two of the rotary feedershave a rotational speed that is separately adjustable. 8) The collectionmeans according to claim 1, wherein the collection means includes a pairof wings pivotally attached on opposite sides of the collection meansand movable about a vertical pivot axis to vary a width of thecollection means. 9) The collection means according to claim 8, whereinthere is a rotary feeder provided for each wing. 10) The collectionmeans according to claim 9, wherein there is a scraper element providedat the bottom of each wing and wherein the rotary feeder is locatedadjacent the scraper element. 11) The collection means according toclaim 8, wherein the wings are able to be biased against a side-wall ofan alley and able to move about the vertical pivot axis in response tochanges in distance between the side-wall and the collection means whenthe apparatus is in use. 12) The collection means according to claim 1,wherein the suction inlet is variable in height with respect to groundlevel. 13) The collection means according to claim 12, wherein thesuction inlet includes a snorkel that permits air to be entrained withthe liquid or semi-liquid materials entering the suction inlet. 14) Thecollection means according to claim 12, wherein each rotary feeder has arotational speed that is adjustable and wherein the rotational speed isdetermined according to the height of the suction inlet and the rate oftravel of the apparatus. 15) The collection means according to claim 1,wherein the protrusions are scoop shaped. 16) The collection meansaccording to claim 1, wherein the protrusions are rigid. 17) Thecollection means according to claim 1, wherein each rotary feeder iselevated with respect to ground level. 18) A method of collecting liquidor semi-liquid materials comprising: a) providing a mobile vacuumapparatus with a collection means comprising: i) a central portionhaving an interior within which the materials are collected; ii) atleast one scraper element at a bottom of the central portion; iii) asuction inlet located at a middle of the central portion; and, iv) aplurality of rotary feeders within the interior of the central portionadjacent the scraper element, b) adjusting a rotational speed of therotary feeders according to the consistency of the materials beingcollected, the height of the suction inlet and/or the rate of travel ofthe mobile vacuum apparatus. 19) The method according to claim 18,wherein each rotary feeder has a vertical axis of rotation. 20) Themethod according to claim 18, wherein the rotational speed of the rotaryfeeders is selected in order to mix thicker semi-liquid materials withthinner semi-liquid materials.